1. Field of the Invention
The invention generally relates to exothermic cutting rods.
2. Description of the Related Art
Exothermic cutting rods presently consist of several different designs. One configuration is to have a tube with a plurality of inner metallic wires disposed around the inner circumference of the tube. A second configuration includes a tube with a plurality of solid metallic alloy wires inside the tube where the tube is fully stuffed with wires.
Cutting rods are used in a variety of environments, which are mostly out in the field. The military uses cutting rods for demolition and tactical operations. SWAT teams use them to breach secure locations by cutting through metal doors and gates. Divers use cutting rods underwater to cut through metal in fabrication and demolition operations.
Cutting rods work by oxidizing certain metals, which gives off a tremendous amount of heat. Some of the cutting rods burn between 7,000 and 10,000 degrees Fahrenheit. One method of using a cutting rod uses compressed oxygen. A tank of compressed oxygen may be attached to a first end of a cutting rod. When the user desires to burn the cutting rod, he may apply a flow of oxygen to the rod and apply heat in excess of the combustion temperature to a second end of the rod. The components of the rod, in the presence of heat and a stream of oxygen, will ignite; the rod components are oxidized, producing light and heat. Much of the cutting rod is consumed during the burning process. If the supply of oxygen is discontinued before the rod has been fully consumed, the flame will go out and the rod will cease to burn.
The oxygen needed for the burning process has typically been pure or almost pure oxygen. Since most of the uses of cutting rods have been in the field, the supply of oxygen is usually in the form of compressed oxygen in a portable tank. In some instances, the tank may be transported and stored in a vehicle. However, other uses require that the oxygen tank be portably attached to the user. For instance, military personnel must be able to personally transport the oxygen tank since many of the applications are in remote locations and dangerous environments. Similarly, a SWAT team member must be able to remain mobile while carrying the tank of oxygen. Tanks of compressed gasses are inherently dangerous; tanks can store a lot of potential energy, which can be released in a variety of ways. Projectiles, manufacturing defects, or damages to parts of the tank or regulator or valve, are all potential hazards. Rapidly releasing the energy will create a dangerous environment for the user and anyone within several yards (or more). When the compressed gas is pure or almost pure oxygen, the danger level is increased as oxygen can greatly accelerate combustion.
Cutting rods can also be used underwater. When used underwater, the desired performance characteristics may be different from those on land. For instance, it may be advantageous to have a cutting rod that has a longer burn time in order to give the user more time to complete the project.
Therefore, there is a need for a cutting rod that requires a reduced amount of oxygen as compared to traditional cutting rods. There is also a need for a cutting rod that requires a reduced percentage of oxygen as compared to traditional cutting rods. Additionally, there is a need for a cutting rod that requires a lower compressed gas flow as compared to traditional cutting rods. Finally, there is a need for a cutting rod for which the combustion is sustainable using an air compressor or no associated compressed gas tank.